add site guide button to WPD

files/templates/sidebar_WPD.html

@@ -47,6 +47,8 @@
 		</div>
 	{% endif %}
 
+	<a class="btn btn-primary btn-block mb-3" href="/post/122529/new-user-welcome-message-supplement-for">SITE GUIDE</a>
+
 	{% if hole and hole.sidebar_html %}
 		<div class="mb-4">{{hole.sidebar_html|safe}}</div>
 	{% else %}